1. Field of the Invention
This invention relates generally to the field of containers adapted to selectively restrict access thereto, and specifically in one exemplary aspect to animal-proof containers for supplies and other materials including, inter alia, food.
2. Description of Related Technology
Under many circumstances, it is desirable to store supplies and materials in a container such that access to the supplies or materials is selectively controlled. This is true of a broad variety of materials including chemicals, pharmaceuticals, and notably supplies taken on outdoor excursions. One particularly difficult application of such “selective access” technology relates to the storage of food and supplies during hiking and camping excursions into wilderness areas where animals are present. Many of these animals, including most notably members of the ursa species (commonly referred to as bears), are amazingly adept at gaining access to such storage containers. Instances of bears ripping apart containers and even automobiles to get at food stored within are now commonplace. The bear is particularly adept at leveraging its great strength, weight, sharp teeth and claws to gain access to literally any type of container. Bears are often excellent climbers as well, thereby affording them substantial mobility in all three dimensions.
While not only destructive and costly, such surreptitious access by bears is also detrimental to the bear population, since (i) the bears can become dependent on the ill-gotten food provided by humans, thereby reducing their ability and tendency to obtain food via natural sources; and (ii) the bears can become increasingly aggressive in their attempts to obtain food, thereby sometimes necessitating their termination as a danger to humans. Aside from the foregoing, even a “low intensity” encounter with a bear seeking food can be traumatic to the hiker or camper, and represents another danger thereto. Many a camping or hiking trip has also been ruined through unexpected loss of supplies, even where no confrontation occurs.
Accordingly, more extreme measures have been implemented in recent years to mitigate the foregoing detriments and threats to both humans and bears. For example, Federal law now requires proper storage of food throughout National Parks (such as the well known Yosemite National Park). The National Park Service strongly advises all backpackers to carry and use approved bear-resistant food storage canisters instead of other traditional methods such as slinging the food/supplies over an elevated tree limb, etc. In some areas use of bear-proof canisters is required (such as above certain elevations within Yosemite).
In response to the aforementioned surreptitious intrusion and access to food and supplies by bears, a variety of different “bear exclusion” technologies have arisen over the years. These are generally classified into three (3) discrete categories: (i) anti-bear canisters; (ii) anti-bear bags; and (iii) hanging or elevated storage. These devices are generally subject to approval by relevant oversight organizations such as SIBBG or SEKI.
Several different types of anti-bear canisters have been developed or proposed. Three commercially available types include the Garcia Model 812 Backpackers' Cache, the so-called “Bearikade” manufactured by Wild Ideas, Inc., and the Tahoe model from Purple Mountain Engineering, Inc. of Palmdale, Calif.
The Model 812 device 100 (FIG. 1) is generally cylindrical in shape, yet with a decided taper from the center region 102 toward its ends (thereby giving somewhat of a “beer barrel” appearance). The completely opaque (black) device is manufactured via an injection molding process, wherein two half-sections are formed of a polymer (Acrylonitrile Butadiene Styrene, or ABS) and then bonded together via an adhesive. In terms of access, one end of the container includes an aperture 104 significantly smaller than the outer diameter of the container, thereby creating a fairly broad rim or lip 106 around the periphery of the aperture. An access hatch or cover 108 is mated into the aperture, using an insert tab and two opposed, mechanically actuated locking mechanisms 110 to secure the cover in place. A screwdriver, coin, or other similar device is required to actuate the mechanisms.
Unfortunately, the Model 812 device suffers from several disabilities, including the aforementioned taper of the container, which makes carrying. very difficult (e.g., restraining straps tend to slide off the container due to the taper). A corresponding carrying case is sold (Model C-12 Carrying Case) in order to carry the Model 812 device, attesting to its difficulty to carry or restrain without an external case. Whether by design or otherwise, this approach adds additional cost to the solution.
The Model 812 design also utilizes the aforementioned cover as part of the structural integrity of the container, the cover 108 bearing some of any compressive force applied to the container as a whole. Unfortunately, the cover can be dislodged when enough lateral compressive force is applied (such as a heavy bear standing on the side of the device with its weight on its front paws). This effect results primarily from differential distortion of the container and the cover.
Another disability associated with the Model 812 device is due to the aforementioned cover 108 being recessed in an aperture is the tendency for rainwater to collect in this recess and enter the container, wetting and spoiling the contents.
Another disability associated with the Model 812 device is the substantially restricted access provided to the user. Specifically, the thick rim or lip 106 previously described acts to make items inserted or removed via the aperture more likely to catch or be hung up on the rim. This is especially true of non-cylindrical or round items, such as freeze-dried food pouches or the like. The edges of such items tend to catch on the rim of the container, thereby requiring the user to fold or bend the item for easier insertion/removal. This is particularly frustrating and debilitating when removing the items from the container, since the aperture is sized not much larger than the diameter of the average human fist, thereby making manipulating such items awkward (or otherwise necessitating “pre-forming” them, such as by using rubber bands or the like).
Additionally, the locking mechanisms 110 of the Model 812 are difficult to operate, and require a separate tool. They also must be properly aligned to replace the cover onto the container body, and are potentially subject to fouling with dirt or other foreign materials. Such locking mechanisms are also comparatively expensive to manufacture.
Additionally, the need to bond the two half sections of the Model 812 together also requires a substantial butt joint that introduces extra bulk and weight to the design with a reduction in useful interior volume (and therefore food capacity).
Lastly, the Model 812 device is also comparatively heavy, owing in large part to the injection-molded/adhesive technology it utilizes. Specifically, in order for the container (and particularly the bonded seam) to sustain sufficient lateral or longitudinal loading, the container material must be made comparatively thicker, especially since it is designed for minimum flexing (i.e., the ABS is not very flexurally robust). This added thickness significantly increases the weight of the container.
The aforementioned “Bearikade®” device 200 (FIG. 2) has a generally similar construction to the Model 812, in that it is substantially cylindrical, and utilizes rotated locking mechanisms 202 to seal the cover 204 to the canister 206. See the discussion of U.S. Pat. No. 6,343,709 provided subsequently herein. However, its shape is cylindrical (no seeming taper), and the container is fabricated using a comparatively complex and expensive technology. Specifically, the container is made of a composite sandwich using an offset seam, taper rolling technique. The container is also cured in autoclave at elevated temperature and pressure. The Bearikade end components principally consist of a 6061 T-6 aluminum hatch, locking collar, and end fittings bonded to the composite carbon-fiber cylinder with high strength epoxy. O-rings are used between the fasteners and hatch, and between the hatch and locking collar. When sealed properly (the seal must not have any debris on the O-rings), the O-rings are under compression and offer a seal against water.
While having good access at the access aperture, the Bearikade device suffers primarily from high cost and complexity of manufacturing, the former being several times the cost of the Model 812 device previously described. It (Bearikade) similarly uses mechanically actuated locking mechanisms (3) which must be operated with a tool or coin. Furthermore, the device is not well adapted to climatic changes in pressure; the aforementioned O-rings, while useful for preventing water intrusion (due in part to the pressure differential across the cover acting to more tightly seal the O-rings when the canister is submerged), also can make the device difficult to open when it is sealed at higher elevation (lower pressure), and then transported to a lower elevation (higher pressure). This “vacuum bottle” effect is highly undesirable.
The Purple Mountain Engineering (PME) “Tahoe” bear canister is made from 6061 aluminum. The canister body is heat treated after assembly, and the top is TIG (Tungsten Inert Gas) welded to the canister body. The cover (lid) is hinged (stainless steel riveted to the top and lid). Closure of the lid is accomplished by a DZUS fastener rated at 600 pounds closure force. As with the other prior art solutions, the Tahoe suffers from several disabilities, including complexity, comparatively high cost and heavy weight (two pounds, six ounces) and small capacity.
The so-called “Ursack®” device is generally representative of the state-of-the-art in anti-bear sack technology. The Ursack TKO model is made of spectra fabric and bolstered with flexible fiberglass ripstop. The standard Ursack is made from aramid fibers woven to enhance puncture and tear resistance to ostensibly thwart a bear's teeth, claws, and strength. However, the Ursack has the flaws of providing no rigid support to protect the materials contained within, and the aramid or other fibers are comparatively costly to manufacture. The Ursack has also proven less than completely effective at frustrating bear intrusion, and also requires that the device be tied to a tree or other immovable structure (lest the bear merely carries the sack off for later efforts at intrusion). See the discussion of U.S. Pat. No. 6,332,713 provided subsequently herein.
A variety of technologies related to animal exclusion and tamper-resistant/sealed containers are present in the patent prior art as well. For example, U.S. Pat. No. 4,203,479 to Mathews issued May 20, 1980 and entitled “Trash bag protector” discloses a device for protecting filled trash bags from attacks by dogs or other animals. The device has a collapsible mesh frame composed of interwoven plastic strands and which presents an open top defined by an upper rim. The open top is closed by eight equally spaced straps whose outer ends are attached to the rim. The inner end of one of the closure straps is provided with an upstanding post upon which the inner ends of the other straps can be installed. Thus installed, the straps extend radially outwardly from the post to the rim and may be locked in place, thereby securing the bags in the protector device.
U.S. Pat. No. 4,801,039 to McCall, et al. issued Jan. 31, 1989 and entitled “Animal proof container” discloses an animal proof container comprising a can having a bottom, a sidewall having an inside surface having a plurality of substantially flat portions each having a recess defined thereby, an outside surface having a corresponding plurality of holes communicating to the recesses and a rim defining an open top. A lid of the container has a cover portion adapted to cover the open top of the can and a plurality of members extending downwardly peripherally from the cover portion, fitting adjacent the inside surface of the can and having lower end portions adjacent the flat portions of the inside surface, the lower end portions being biased outwardly towards the flat portions sufficiently to proceed into the recesses when the lid is pushed fully downwardly onto the can. The lid is biased normally upwardly relative to the can sufficiently for preventing the lower end portions from entering the recesses. Food stored in such a container is ostensibly protected from the attacks of animals, including large animals such as bears. The container can also be made relatively light in weight.
U.S. Pat. No. 5,344,109 to Hokoana, Jr. issued Sep. 6, 1994 and entitled “Apparatus for the engagement and suspension of a bag above the ground for the suspendable storage of items within the bag” discloses an apparatus for suspending conventional trash bags and other bags above the ground for the storage and/or disposal of a variety of items including camping supplies and food. The apparatus comprises a support frame for securing the rim of the bag thereto and suspension arms coupled to the support frame through the use of engagement hooks for hanging the bag above the ground. The support frame comprises a first aperture for insertion of the rim of the bag therethrough, the rim wrapped around the sides of the support frame such that the bag opens through the first aperture. To protect the items inside the bag from weather and animals, the apparatus further includes a cover frame with a second aperture disposed on top of the support frame and a lid for covering the second aperture. With this arrangement, the engagement hooks are used to engage and secure the corresponding corners of the support frame and the cover frame with the rim of the bag firmly secured therebetween. The apparatus may further include upholding means for coupling one end of the suspension arms together and engaging a support structure for suspension of the apparatus, the upholding means comprising one of a variety of attachment members and having a length adjustment member for facilitating attachment of the apparatus to an appropriate support structure.
U.S. Pat. No. 5,411,161 to Fish, Jr. issued May 2, 1995 and entitled “Container having a twist-locking cover” discloses a refuse device includes a cover which can be locked to the container of the device by rotating the cover on the container. The cover includes a top portion, a collar extending downwardly from the top portion, and two tabs attached to the collar, spaced apart from the top portion, located opposite each other, and extending inwardly from the collar. The container includes a sidewall terminating in an upper edge, a closed bottom attached to the sidewall opposite the upper edge, an outwardly extending rim attached to the upper edge of the sidewall, and an upwardly extending lip attached to the rim opposite the sidewall. The lip includes two diametrically opposite channels through which the tabs move when the cover is placed on or removed from the container. The lip also includes six grooves, two of which flank the first channel, two of which flank the second channel, and two of which are positioned intermediate the first and second channels. The latches rest within the two intermediate groove when the cover is first placed on the container. The latches rest in two of the grooves flanking the channels when the cover is locked to the container. In this locked position, the cover cannot be lifted from the container, and resists rotation on the container.
U.S. Pat. No. 5,638,977 to Bianchi issued Jun. 17, 1997 and entitled “Assembly for securing a lid to a container” discloses a lid to be attached to a container, a garbage can for example, wherein the lid is secured by means of a system comprising holes placed in the lid rim in alignment with corresponding holes in the top of the container. A conduit is provided on the underside of the lid in alignment with the holes in the lid and the holes in the container. A securing rod passes through the conduit and the holes in the lid and container to secure the lid to the container. In use, the holes of the lid rim and the holes of the container are in registration with each other.
U.S. Pat. No. 5,950,981 to Judy issued Sep. 14, 1999 and entitled “Bear bag system” discloses a bear bag system for protecting a supply of food while camping. The device includes a length of nylon rope having opposing free ends. A bag of rocks is securable to one of the free ends of the length of nylon rope. Two supplemental bags are provided for storing food. Two lengths of curtain cord adjustably couple the supplemental bags with respect to the length of nylon cord.
U.S. Pat. No. 6,332,713 to Cohen issued Dec. 25, 2001 and entitled “Lightweight bear bag” discloses a lightweight food sack (e.g., the aforementioned “Ursack”) made from puncture and tear resistant fabric sewn with high strength thread and secured with an abrasion resistant cord. The food sack is closed by tightening the cord, which encircles the top of the sack in a hem and emerges through a grommet. The cord is secured by means of a cord lock and an overhand knot (20). Excess cord is then tied with a secure knot to a fixed object, such as a tree, so that the sack cannot be removed by a bear.
U.S. Pat. No. 6,343,709 to DeForrest, et al. issued Feb. 5, 2002 and entitled “Impact resistant sealable container” discloses an impact resistant, sealable canister (the aforementioned “Bearikade” being one embodiment thereof) comprising a wall structure having a lower edge portion joined to a base. A receiving collar is joined to an opposing top edge portion of the wall structure. The receiving collar includes an annular channel and an inner shoulder having fastener pads. The pads have fastener openings and stationary connector elements. A container lid releasably seals against the collar by operation of fastener parts retained in the lid that engage the collar connector elements. Gasket materials adjacent the collar periphery and around the fastener parts function to provide a reusable sealed canister useful for water activities and other outdoor involvements.
Despite the variety of different techniques existing under the prior art, there still exists a need for an animal exclusion container, ideally having the following attributes: (i) light weight; (ii) low cost; (iii) ease of access (i.e., no particular tools required); (iv) ready access for objects of varying shape and composition); (iv) ease of carrying; and (v) climatic flexibility and resistance.